Title says it all. Salt system is all Jandy and about 7 years old. The main pump is on a 12h On and 12h Off cycle. The GFI trips randomly, around once a week, maybe a bit less often. It has never tripped while operating, only in morning when the iAqualink program does a morning start. It has never tripped while running. The pool electrician replaced GFI and entire outlet, cable and box in case some rain was getting in. I understand how GFI works and am puzzled why it never trips once operating (even during torrential downpours and we have had a lot). I thought maybe it was due to an inductive surge on startup happening randomly at voltage peak in the AC cycle. If a true ground fault with a high resistance motor winding short problem, wouldn't this also happen randomly during the day?